Nitric ester explosive composition containing fume reducing agent

ABSTRACT

A gelatin explosive composition of matter containing liquid explosive nitric ester material characterised in that said composition comprises an amount of at least one fixative or fume reducing agent sufficient to reduce the volatility or fluidity of said nitric ester material.

United States Patent [1 1 Sujansky NITRIC ESTER EXPLOSIVE COMPOSITION CONTAINING FUME REDUCING AGENT [75] Inventor: Vladimir Sujansky, Melbourne,

Australia [73] Assignee: ICI Australia Limited, Melbourne,

Victoria, Australia- [22] Filed: June 5, 1972 [21] Appl. No.: 259,604

[30] Foreign Application Priority Data June 28, 1971 Australia 5238 [52] US. Cl 149/103, 149/88, 149/104, 149/106, 149/107 [51] Int. Cl C06h 3/02 [58] Field of Search 149/88, 104, 103,

[451 Aug. 28, 1973 [56] References Cited UNITED STATES PATENTS 2,004,941 6/1935 Hale 149/103 X Primary Examiner-Stephen J. Lechert, Jr. Anorney-Cushman, Darby & Cushman [57] ABSTRACT NITRIC ESTER EXPLOSIVE COMPOSITION CONTAINING FUME REDUCING AGENT This invention relates to gelatin type dynamite compositions.

Dynamites produced for industrial uses, for example for mining or for tunnelling, must be manufactured to provide a variety of specific characteristics such as plasticity, density and explosive strength. Because of the requirements of commercial users that for many operations the explosive composition be solid, cohesive and deformable the so-called gelatin dynamites constitute a very important type of dynamite. Gelatin compositions are produced by gelatinizing' a liquid explosive nitric ester material with nitrocellulose of suitable characteristics and incorporating therein a number of solid materials. The solids which have been most frequently incorporated are oxidizing salts, combustible carbonaceous materials, stabilisers, thickeners and fillers. Nitroglycerine and ethylene glycol dinitrate and mixtures thereof are the most commonly used liquid explosive esters. Such esters, or mixtures thereof, may also be modified by additives such as nitrobenzene, nitrotoluene, dinitrotoluene or trinitrotoluene. There may also be added to such gelatin dynamite compositions plasticity promoting agents such as for example the condensation products of ethylene oxide with phenols, alcohols, amines, carboxylic acids, and amides or alkylolamides of carboxylic acids. The completed blend is of a plastic consistency and is packaged in waxed paper shells usually by an extrusion process. 'A very important type of gelatin dynamites are the so-called ammonia gelatins where a portion of the liquid explosive nitric ester is replaced by ammonium nitrate. Similarly sodium nitrate may be used to prepare the so-called sodium nitrate gelatins.

Whilst such gelatin dynamites have been used widely over a long period of time they have been unsatisfactory in respect to certain aspects. Thus for example the liquid nitric ester tends to remove itself from the composition by exudation or volatilization. The effects of this tendency on operatives handling the explosive are well known and lead to headaches and nausea.

We have now found that this disadvantage currently inherent in gelatin dynamites may be reduced considerably or even eliminated in some instances when there is added to a gelatin dynamite an amount of material which acts as a fixative or a fume reducing agent. By a fixative or fume reducing agent we mean a material which acts on a liquid explosive nitric ester so as to reduce the volatility or fluidity of said ester. Suitable fixatives are those used in the perfume industry where when added to a perfume they prevent the too rapid volatilization of its various components and tend to equalize'the rates of volatilization of these components. For many years the leading fixatives were the animal products ambergris, civet, musk and castoreum; such fixatives are suitable for use in our compositions but suffer somewhat in that their unit cost is high. Other fixatives which may be used include the oleoresins such as oakmoss, benzoin, or styrax. Essential oils such as vetivert, patchouli and orris may also be used as may many synthetically produced materials such as for example the artificial musk compounds. Long chain esters are also useful.

Accordingly we provide a gelatin explosive composition of matter containing liquid explosive nit'ric ester material characterised in'that said composition comprises an produce of at least composition fixative or fume reducing agent as hereinbefore defined sufficient to reduce the volatility or fluidity of said nitric ester material.

Artificial musk compounds are particularly suitable for use in our gelatinized explosive compositions. Accordingly in a preferred embodiment of our invention we provide a gelatin explosive composition of matter as hereinbefore described wherein the fixative or fume reducing agent is at least one artificial musk compound. By artificial musk compound we mean compounds selected from the group consisting of 2,6-dinitro-3- methoxy-4-tert.butyl toluene, 3,5-dinitro-2,6-dimethyl- 4-tert.butylacetophenone, 2,4,6-trinitro-1,3-dimethyl- 5-tert.butylbenzene or 2,6-dinitro-3,4,5-trimethyltert- .butylbenzene. Whilst it is convenient to incorporate these artificial musk compounds themselves into our compositions it lies within our invention to incorporate into our compositions 3-methoxy-4-tert.butyltoluene, 2,6-dimethyl-4-tert.butylacetophenone, 1,3-dimethyl- 5-tert.butylbenzene, 3,4,S-methyl-tert.butylbenzene or nitro derivatives thereof wherein said derivatives contain less nitro groups than the musk derivatives referred to above. Such materials are then converted in situ at least in part to the musk derivatives enumerated above during detonation of the composition and act as fixatives or fume reducing agents in a manner similar to that of the musk derivatives themselves.

The amount of fixative or fume reducing agent used in our compositions varies with the type of fixative or fume reducing agent and the composition to which it is added. Thus in instances where the proportion of liquid explosive nitric ester is comparatively high or wherein there is a relatively large amount of an ester such as ethylene glycol dinitrate with an appreciable vapour pressure it may be desirable to use larger amounts of fixative than when lesser amounts of ester are used. Amounts in the range from 0.1 to 5% w/w of the total composition are useful although under certain circumstances larger amounts may be used. We prefer that the amount be in the range from 0.2 to 3% w/w of the total composition.

The nature of the gelatin explosives in which our fixatives or fume reducing agents are incorporated is not narrowly critical. Thus all gelatin compositions known to be satisfactory as explosives may be used as the basic composition with which our fixatives or fume reducing agents may be admixed. Satisfactory gelatin explosives according to our invention containing liquid explosive nitric ester material in the range from 8% to 51% have been prepared. Particularly useful compositions are those containing from 12 to 20% w/w of liquid explosive nitric ester. lt is sometimes convenient to use a mixture of esters. Thus for example mixtures of nitrogylcerine and ethylene glycol dinitrate may be used. Typical mixtures of these materials are those wherein the ratio of the weight of nitroglycerine to the weight of ethylene glycol dinitrate is in the range from 1:9 to lzl. The ratio of components in such a mixture is substantially a manner of economics, although for use in a particular application it may be desirable to choose a particular ratio which confers the desired characteristics, such as explosive power or sensitivity to detonation, to the composition. The upper limit of the concentration of liquid explosive nitric ester or a mixture or modification of liquid explosive nitric esters is merely a matter of economics.

THe nitrocellulose used in our compositions should be of the type conventionally used in explosives and should be present in quantity sufficient to form a thickened viscous fluid when the liquid nitric ester material is partially gelatinized by solution of the nitrocellulose therein. We have found that amounts ranging'from 0.4 to 3.5% w/w of the composition are satisfactory and amounts as little as 0.2% may be used for example when the amounts of liquid explosive nitric ester present is low for example 8.0% w/w.

We prefer that the oxygen releasing salt be chosen from the nitrates of ammonium or the alkali metals and of these we prefer ammonium nitrate and sodium nitrate. The particle size and shape of the oxygen releasing salt is not critical and is well known from the art of inorganic nitrate manufacture; powders and ground prilled particles are satisfactory. Suitably the amount of oxygen releasing salt in our compositions is such that it consitutes 35% w/w or more of the composition. Thus, for example, satisfactory compositions may be obtained when the total amount of oxygen releasing salt, or mixtures of such salts, is in the range from 60 to 80% w.w, often from 70 to 75% w/w, of the total composition.

Carbonaceous combustible materials should preferably be used in finely divided form and amongst suitable products, there may be mentioned asphalt, naphthalene, sugar, urea, hexamethylenetetramine, cellulosic ucts, for example, flours, dextrins or starches. Suitably they may be present in amount in the range from 3 to 12% w/w, preferably from 5 to 9% w/w, of the total composition.

Where desirable, it is convenient to add to the compositions according to our invention, further reagents such as water, in amounts in the range from 0 to 1.5 part; conventional thickeners, for example, guar gum, in amounts in the range from O to 2 parts; conventional fillers for example, calcium carbonate, china clay, barium sulphate and ammonium phosphates in amounts in the range from 0 to 10 parts; modifiers for the liquid explosive nitric ester for example, dinitrobenzene, dinitroethylbenzene, nitrotoluene, dinitrotoluene, trinitrotoluene or dinitroxylene in amounts in the range from 0 to 5 parts; plasticity promoting agents for example the condensation products of ethylene oxide with alkylphenols and derivatives thereof, alcohols, amines, carboxylic acids, and amides or alkylolamides of carboxylic acids in amounts in the range from 0 to 2 parts; polymeric materials; or esters, such as amyl acetate, octyl butyrate, isoamyl isobutyrate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, dioctylphthalate or 'diisooctylphthalate in amounts in the range from 0 to 1 part, all per 100 parts by weight of the final mixture.

We also provide a process of manufacturing a gelatin explosive composition of matter containing liquid explosive ester material which process comprises adding to and admixing with a gelatin explosive composition of matter containing liquid explosive nitric ester material an amount of a fixative or fume reducing agent, preferably an artificial musk compound, as hereinbefore defined, sufficient to reduce the volatility of fluidity of said nitric ester material.

The compositions according to this invention are plastic masses, ranging in plasticity from soft'to stiff materials such as sawdust or woodmeal, or cereal prodand dry which are extrudable in a deformable, solid and cohesive form. They are advantageous over compositions of the prior art in that, because of the incorporation therein of an amount of fixative 0r fume reducing agent, they have a reduced tendency to lose their content of nitric explosive ester material either by exudation or volatilization. This characteristic is of great benefit to persons handling the compositions in so far as it reduces the health hazard to such persons and also minimizes personal inconvenience to them.

A further disadvantage of the gelatinized explosive compositions of the prior art is that such compositions when detonated produce toxic fumes such as carbon monoxide, oxides of nitrogen, ammonia, hydrogen cyanide and the like. Such toxic fumes are hazardous to operatives working in confined spaces such as in underground tunnels. It is common practice to pass streams of air through such spaces subsequent to a blasting operation and to delay entry of persons to the working site until the concentration of toxic gases has been reduced to a safe level. Such practice is costly both in money and time and it is desirable that the initial concentration of toxic gases after detonation be kept to as low examples level as possible to reduce costs and time in tunnelling. Certain of the compositions according to our invention have the unexpected advantage that when such compositions are detonated, for example during a tunnelling operation, the and concentration of fume and toxic gases resulting from the detonation in markedly less than the concentration of fume and toxic gases produced by compositions of the prior art. Such a characteristic results in an improvement in the rate of work since less time elapses between the time of detonation and the time when the toxic gases are sufficiently removed from the work area by conventional air flow means to give an atmosphere in which it is safe to work.

Our invention is now illustrated by, but not limited to, the following examples in which parts and percentages are expressed on a weight basis unless otherwise specified. Examples 17 and 19 are not within our invention and are included for the purposes of comparison.

EXAMPLES 1 TO 15 INCLUSIVE Using a conventional ribbon mixer, 15 lb. of a gelatinized explosive composition was prepared by, mixing the substances set out in Table l in proportions as set out in Table l. The composition was then extruded into paper shells to form cartridges of the explosive composition using a cartridging machine conventionally used in the manufacture of explosives. Details of the explosive characteristics of the compositions are set out in Table 1.

Notes of Table l l. The ammonium nitrate used had various sieve characteristics and these are designated as set out below.

= ground prilled ammonium nitrate of which 99% passed a No. 100 E58 sieve and 20% was retained on a No. 200 1388 sieve.

C coarse ammonium nitrate of which 50% was retained on a No. 18 B88 sieve and 90% was retained on a No. 36 B88 sieve.

F fine ammonium nitrate of which passed a No. 36 B58 sieve and 30% passed a No. I00 888 sieve.

superfine ammonium nitrate of which 20% passed No. 72 B88 sieve, 82% was retained on a 5 6 No. 150 888 sieve and 98% was retained on a Example 7 was prepared and converted into explosive No. 240 BSS sieve. cartridges by two operatives who had not yet become in Example 15 a mixture of two types of ammonium accustomed to the symptons usually induced by liquid nitrate was used and the mixture consisted of 35 parts nitric explosive ester containing explosives. It was obof coarse and 22.5 parts of fine ammonium nitrate. 5 served that after 2 hours of work neither operative 2. For convenience the fixative or fume reducing complained of induced headache.

a ent is referred to as W, X, Y or Z wherein 7 2,6-dinitro-3-methoxy-4-tert.butyl toluene EXAMPLE 17 X 3,5-dinitro-2,6-dimethyl-4-tert.butyl aceto- The procedure of Example 16 was repeated for the phenone i purposes of comparison, but the composition prepared, Y 2,4,6-trinitro-l ,3-dimethyl--tert.butyl bennot within our invention, was identical to that of Example 7 except that the fixative component was omitted.

zene Z 2,6-dinitro-3,4,5-trimethyl-tert.butyl benzene Both operatives complained of a headache condition 3. A.D.C is a contraction of the well known Ardeer after working with this composition for minutes.

Double Cartrid e Test and is a measure of the senl5 sitivity of the eiplosive. The higher the value, the EXAMPLE l8 more sensitive to detonation is the explosive. In an experimental blasting chamber 5 feet high X 3 4. VOD is the velocity of detonation expressed in feed wide X 35 feet long situated in a basalt rock formametres per second when determined by the Daution there were detonated 21 cartridges prepared from triche method. a composition according to Example 10. The total 5. 8.6 strength represents the power of the exploweight of explosive detonated was 6 lb. 30 seconds sive compared to a blasting gelatin containing after the detonation asampling probe was inserted into 9l .2% w/w nitroglycerine. the chamber and a portion of the atmosphere was with- 6. Alkanate" 3SN5 is a Trade Mark for a condendrawn from the chamber. Analysis of the atmosphere sate of 1 mole of the sulphate of nonylphenol soso withdrawn showed that it contained, on a volume badium salt condensed with about 5 moles of ethylsis, 200 parts per million (ppm) of carbon monoxide ene oxide. and i5 ppm of oxides of nitrogen. No ammonia, nitro- 7. Teric 18Ml0 is a Trade Mark for a condensate glycerine or ethylene glycol dinitrate was detected. of 1 mole of stear lamine with about 10 moles of 4 ethylene oxide. y EXAMPLE 8. Teric" CME3 is a Trade Mark for a condensate The general procedure of Example 18 was repeated of 1 mole of a coconut acid alkylolamide with except that the composition of Example 10 was reabout 3 moles of ethylene oxide. placed bya comparative composition. The compara- TABLE 1 Example number 1 2 3 4 5 7 8 9 10 11 12 13 14 15 Nitroglycerine -1.9 1.9 1.9 1.9 1.9 1.9 9.5 9.5 9.5 9.5 19.0 12.0 8 0 12.0 27 "1 Ethylene glycol dinitrate 17. 1 17.1 17.1 17.1 17.1 17.1 9. 5 9. 5 9. 5 9. 5 8. 0 Ammonium nitrate. 69. OF 70. 0C 71. 0F 67. OS 59. OS 61. 63. OS 63. 0F 62. 2F 61. 2F 62 0F 64. OS 79. 7F 76. 4F 57 5FC Sodium nitrate 4. 0 6. 0 6.0 6. 9 6. 0 6. 0 6. 0 6 0 4. O 6. 0 Nitrocellulose. 1. 0 5 9. 0 5 5 0. 8 v-Nitrotoluene Dinitrotoluene.. Trinitrotoiuene. Dinitrowlene..." Tamarind flour. Wheat flour..... Woodmeal Starch Rosin Sulphur Calcium carbonate Diammonlum phosphate Guar gum Water Amylacetate "Alkanate 3SN5. Torin 181110.... "Terlc CME3 Fixativc Typo. Z Y Fixatlvc 2.0 0. 0 Density (gnu/cc.) 1.29 1.35 .50 13.6. strength 74 76 Initial ADC 5 7% 5% 4 Initial \ODXIO 39 34 37 22 ADC after 2 months storage. 1% 2% 2% 3% \'OD 10 after 2 months storage 25 23 30 23 A DC after 4 months stomps. 1% 2 1% 314 OD 10 alter 4 mont is storage 20 19 23 2 EXAMPLE 16 We composition, not within our invention, was identical with the composition of Example 10 except that it tives in reducing health hazards and personal discorncontained no 2,4,6-trinitro-l.3-dimethyl-5-tert.butyl fort to operatives working with gelatine explosive combenzene. The atmosphere after detonation of the compositions. Using conventional commercial apparatus position was found to contain, on a volume basis, 260 and processing conditions a composition according to ppm of carbon monoxide, 30 ppm of oxides of nitro- This example demonstrates the efficacy of our addigen, 4 ppm of ammonia and ppm of nitric ester calculated as a 50:50 mixture of nitroglycerine and ethylene glycol dinitrate.

EXAMPLES 20 TO 30 ity or fluidity of said nitric ester material, said agent being selected from the group consisting of 2,6-dinitro- 3-methoxy-4-tert.butyltoluene, 3,5-dinitro-2,6- dimethyl-4-tert.butylacetophenone, 2,4,6-trinitro-l 5 3-dimethyl-5-tert.butylbenzene, and 2,6-dinitro-3,4,5- In each of these examples the general procedure of trimethyl-tert.butylbenzene. Example 16 was repeated except that instead of prepar- 2. A composition of matter according to claim 1 ing a composition according to Example 7 composiwherein the amount of fixative or fume reducing agent tions were prepared using proportions of ingredients as is in the range from 0.1 to 5% w/w of the total composiset out in Table 2. It was observed in each instance that 10 tion. these compositions were less prone to induce head- 3. A composition of matter according to claim 1 aches in the operatives than were comparative compowherein the amount of fixative or fume reducing agent sitions prepared in a similar manner but without incoris in the range from 0.2 to 3% of the total composition. porating the fixative component therein. 4. A composition of matter according to claim 1 Notes on Table 2 wherein the amount of liquid explosive nitric ester mal. The letters F, S, Y and Z have the same signifiterial constitutes from 8 to 51% w/w of the composicance as in Table 1. tion. 2. Alkenate" D is a Trade Mark for a sodium salt of 5- A composition of matter according to claim 1 d d lb l h ni id wherein the amount of liquid explosive nitric ester ma- 3, T i 18M20 i a T d M -k f a nd t 20 terial constitutes from 12 to 20% w/w of the composiof 1 mole of octadecylamine with about 20 moles nf th l id 6. A composition of matter according to claim 1 4 T -i N8 i a T d M k f a condensate f 1 wherein the liquid explosive nitric ester material commole of nonylphenol with about 8 moles of ethylprises r gly neene id 7. A composition of matter according to claim 1 5 5 is a Trade k fo a condensate of 1 wherein the liquid explosive nitric ester material coml of l h l i h about 5 moles f h l prises a mixture of nitroglycerine and ethylene glycol oxide dinitrate.

TABLE 2 Example number 20 21 22 23 24 25 29 30 Nitroglycerine 3. 9 5.1 .9 l9. 0 9. 1. 9 .9 Ethylene glycol dinitrate 35.5 45.5 .1 9. 17.1 1 Ammonium nitrate. F F .5 F 2.

Sodium nitrate Nitrocellulose" .c Dinltrobenzenu Dinitrotoluene Dinitroethylbenzene Wheat, fiour Woodmeal Clia1k Barytcs Diammonium phosphate Magnesium sulphate Dibutylphthalate... "Alkonatv" D "Toric" 18M20.

mic r .5

Fixative 0.3Y 0.4Y 0.25Y 0.25Y 0.251 on 0.2Y 0.2Y 0.2a! 0.25Y 0.2Y+0.1Z

lclaim: 8. A composition of matter according to claim 7 l. A gelatin explosive composition containing liquid explosive nitric ester material selected from the group consisting of nitroglycerine and ethylene glycol dini-. trate and comprising an amount of at least one fixative or fume reducing agent sufficient to reduce the volatilwherein the ratio of the weight of nitrogylcerine to the weight of ethylene glycol dinitrate is in the range from 1:9 to 1:1. 

2. A composition of matter according to claim 1 wherein the amount of fixative or fume reducing agent is in the range from 0.1 to 5% w/w of the total composition.
 3. A composition of matter according to claim 1 wherein the amount of fixative or fume reducing agent is in the range from 0.2 to 3% of the total composition.
 4. A composition of matter according to claim 1 wherein the amount of liquid explosive nitric ester material constitutes from 8 to 51% w/w of the composition.
 5. A composition of matter according to claim 1 wherein the amount of liquid explosive nitric ester material constitutes from 12 to 20% w/w of the composition.
 6. A composition of matter according to claim 1 wherein the liquid explosive nitric ester material comprises nitroglycerine.
 7. A composition of matter according to claim 1 wherein the liquid explosive nitric ester material comprises a mixture of nitroglycerine and ethylene glycol dinitrate.
 8. A composition of matter according to claim 7 wherein the ratio of the weight of nitrogylcerine to the weight of ethylene glycol dinitrate is in the range from 1:9 to 1:1. 